CAT (QA) PYQs

On a long stretch of east-west road, $A$ and $B$ are two points such that $B$ is $350$ km west of $A$. One car starts from $A$ and another from $B$ at the same time. If they move towards each other, then they meet after $1$ hour. If they both move towards east, then they meet in $7 \mathrm{hrs}$. The difference between their speeds, in km per hour, is

In a car race, car $A$ beats car $B$ by $45 \mathrm{~km}$, car $B$ beats car $C$ by $50$km, and car $A$ beats $C$ by $90 \mathrm{~km}$. the distance (in km) over which the race has been conducted is

Two persons are walking beside a railway track at respective speeds of $2$ and $4 \mathrm{~km}$ per hour in the same direction. A train came from behind them and crossed them in $90$ and $100$ seconds, respectively. The time, in seconds, taken by the train to cross a stationary object?